Bispectral analysis of electroencephalogram signals during recovery from coma: Preliminary findings

Schnakers, Caroline; Majerus, Steve; Laureys, Steven

doi:10.1080/09602010443000524

Cited by 32 publications

(18 citation statements)

References 21 publications

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“…Quantitative EEG (qEEg) techniques process the data and retrieve features not visible on the raw traces. qEEG has shown group-level differences between VS and MCS in time domain, power spectrum, connectivity, 110,111 entropy 112 and bispectral index 113,114 measurements, but does not presently offer reliable diagnostic or prognostic information at the single-patient level.…”

Section: Electrophysiologymentioning

confidence: 99%

Disorders of consciousness after acquired brain injury: the state of the science

et al. 2014

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| The concept of consciousness continues to defy definition and elude the grasp of philosophical and scientific efforts to formulate a testable construct that maps to human experience. Severe acquired brain injury results in the dissolution of consciousness, providing a natural model from which key insights about consciousness may be drawn. In the clinical setting, neurologists and neurorehabilitation specialists are called on to discern the level of consciousness in patients who are unable to communicate through word or gesture, and to project outcomes and recommend approaches to treatment. Standards of care are not available to guide clinical decision-making for this population, often leading to inconsistent, inaccurate and inappropriate care. In this Review, we describe the state of the science with regard to clinical management of patients with prolonged disorders of consciousness. We review consciousness-altering pathophysiological mechanisms, specific clinical syndromes, and novel diagnostic and prognostic applications of advanced neuroimaging and electrophysiological procedures. We conclude with a provocative discussion of bioethical and medicolegal issues that are unique to this population and have a profound impact on care, as well as raising questions of broad societal interest.

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Section: Electrophysiologymentioning

confidence: 99%

Disorders of consciousness after acquired brain injury: the state of the science

et al. 2014

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“…In addition, an empiric BIS cut-off value of 50 was proposed to differentiate unconscious patients (coma, persistent vegetative state) from conscious (minimally conscious state) patients [8][9][10]. In our patient, the high baseline BIS value was neither in accordance with his GCS of 4, nor with the established cut-off value since our patient was in coma with a BIS between 90-100 and clearly it could not be indicating consciousness.…”

Section: Discussionmentioning

confidence: 80%

Bispectral Index Monitoring in a Severe Comatose Patient During Surgery

Galinski¹,

Barrera²,

Valls³

et al. 2007

TOATJ

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Abstract:A comatose patient required a tracheostomy. His Glasgow Coma Score was 4 and he was intubated with mydriatic and isochoric pupils, without corneal and light reflexes. Two previous EEGs showed signs of severe and diffuse encephalopathy (arreactive delta and theta rhythms) and there were no somatosensory evoked potentials recordable at the scalp. When the tracheostomy procedure was carried out, the Bispectral Index (BIS) helped to titrate the hypnotic and analgesic requirements keeping the haemodynamic parameters stable. IMPLICATIONS STATEMENTA comatose patient had to undergo surgery. We guided the hypnotic and analgesic requirements by the bispectral index.The bispectral index (BIS) has been used in severely comatose patients as an assessment of the onset of brain death [1]. Moreover, in patients in a persistent vegetative state, BIS has helped to guide anaesthetic depth during surgery [2]. We show the clinical state, electrophysiological tests and the anaesthetic management of a patient in coma after cardiac arrest due to near drowning, who needed to undergo a tracheostomy. CASE REPORTA 72 yr old 80 kg male, was resuscitated (advanced CPR lasting 40 minutes). He was endotracheal intubated with a Glasgow Coma Score (GCS) of 3, his pupils were mydriatic and isochoric, without corneal or light reflexes. At the intensive care unit (ICU) and for two weeks, he went on ventilated using pressure support mode, because he had spontaneous breathing. The neurological condition evolved to a GCS equal to 4 + tube, with a rigid posture, sporadic passive eye opening and weak withdrawal responses to the nociceptive stimulus. Two EEG were carried out, the first, 24 h after admission to ICU and the second a week later, both showed signs of severe and diffuse encephalopathy (arreactive delta and theta rhythms). The somatosensory evoked potentials recorded at the scalp, were absent when the posterior tibial nerves were stimulated.After two weeks, it was decided to perform a tracheostomy. At the operating theatre, the conventional monitoring went on while the BIS was measured with an Aspect A-2000 monitor / BIS TM quatro sensor (Aspect Medical Systems Inc., Newton MA). We guided the hypnotic and analgesic requirements by BIS, observing the haemodynamic parame-*Address correspondence to this author at the Department of Anaesthesiology, Hospital Universitario del Mar, UAB, Paseo Marítimo 25-29 08003 Barcelona, Spain; Tel: 34932483350; Fax: 34932483617; E-mail: 18569@imas.imim.es ters, too. At the beginning, the systolic blood pressure (SBP) was higher than 200 mmHg while BIS values ranged from 90 to 100, so we used intravenous labetalol (5 mg) and administered cis atracurium (4 mg), to adapt the mechanical ventilation and to attenuate the rigidity (EMG activity 50). Thus, the SBP decreased to150 mmHg while the BIS and EMG values fell to almost 50 and 30 respectively. As BIS and EMG values were restored, we began to administer sevoflurane at 1,5 % end -tidal concentration, a dose that allowed him to reach an anaesthesia depth r...

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“…In a recent study by Schnakers and colleagues, an empirically defined bispectral index cut-off value of 50, differentiated unconscious patients (coma or VS) from conscious patients (MCS or emergent MCS) with a sensitivity of 75% and specificity of 75%. These preliminary findings are encouraging in the search for electrophysiological correlates of consciousness following severe acquired brain injury [45]. Work continues to determine if quantification of power and phase relationships by bispectral analysis enable the bispectral index to be used to measure functional disconnections among cortical areas, given that power and coherence in the δ and τ bands increase as a sign of cortical awareness [46].…”

Section: Prognostication and Late Recoveriesmentioning

confidence: 96%

Neurorehabilitation Issues in States of Disordered Consciousness Following Traumatic Brain Injury

Zasler

2006

Future Neurol.

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The assessment and care of persons with disorders of consciousness (DOC) following catastrophic traumatic brain injury is often difficult and filled with both challenges and potential controversies. Rates of misdiagnosis of low-level neurological state (LLNS) patients with signs of awareness as being vegetative have been noted to be unacceptably high and call for better education and training regarding the assessment methodologies of individuals with DOC. Clinician knowledge regarding prognostication and neural recovery from LLNSs following traumatic brain injury is often lacking, as is awareness of the neurorehabilitative interventions that can potentially facilitate recovery, as well as minimize morbidity and mortality in this unique population of neurological patients.

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Bispectral analysis of electroencephalogram signals during recovery from coma: Preliminary findings

Cited by 32 publications

References 21 publications

Disorders of consciousness after acquired brain injury: the state of the science

Disorders of consciousness after acquired brain injury: the state of the science

Bispectral Index Monitoring in a Severe Comatose Patient During Surgery

Neurorehabilitation Issues in States of Disordered Consciousness Following Traumatic Brain Injury

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